NPA 2021-01

Rotorcraft chip detection systems (RMT.0725 — Subtask 1)

The objective of this Notice of Proposed Amendment (NPA) is to ensure that the chip detection systems installed in rotorcraft rotor drive systems achieve an acceptable minimum level of effectiveness.

This NPA proposes to introduce new objective-based certification specifications (CSs) for the performance of chip detection systems, and the associated acceptable means of compliance (AMC) and guidance material (GM).

Ultimately, the target is for rotorcraft rotor drive systems to feature systems capable of effectively detecting ferromagnetic particles indicating the incipient failure or degradation of internal gearbox components. 

The proposed amendments are expected to increase the safety of rotorcraft rotor drive systems by improving their designs.